What do I do??? I am torn between two cards . . .

What do I do??? I am torn between two cards . . .

Looking at the deck presets and reading the comments of both cards, I have been repeatedly told to replace my Luba with Leviatonn. First, some background: I am primarily a GHEIST user, and I am trying to bring my deck down to 10 cards. I am seeing that this is a lot harder than it looks, because there are so many excellent GHEIST cards. Anyway, I have been told to replace Luba with Leviatonn, and frankly, I don't want to. I have broken so many backs and tricked so many people with Luba, and now I have to replace her with a card that has one less power and potentially 3 less damage (if Luba gets 8 damage from an enemy)? It doesn't seem like a worthwhile trade. I have considered keeping both, but that means less room for my 10-card deck that already is down to 9 with Eyrik. What should I do???